Is the Wave Function Real? Evidence from the Frankenstein Photon Experiment

[DevilsAvocado]

So I conclude that the wave function is quite real. Your thoughts?

If I were a philosopher, I would start like this: Please define real & reality.
(but I’m just a rambling layman, so I jump right-on the interesting stuff)

Great 'Frankenstein-gadget' you got there DrC! I’m curious and do have questions:


1) I’ve quickly read the Eberly paper, and understood < 50% , but I must ask about your "polarizing beam splitter". In the paper Eberly describe the "Analyzer loop", as "Calcite analyzer" + "Reversed analyzer", and you have only 'one part' – the polarizing beam splitter? Wouldn’t that count as 'measurement' on Alice & Bob, 'destroying' the wavefunction/entanglement? If we compare with the http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser" the interference pattern is lost if we don’t apply another beam splitter to join the (virtual) paths of the photon:

Wikipedia - Delayed choice quantum eraser
In the two diagrams to the right a single photon is emitted at the yellow star, passes through a 50% beam splitter (green block) that reflects 1/2 of the photons, and travels along two possible paths, depicted by the red or blue lines.

In the top diagram, one can see that the trajectories of photons are clearly known — in the sense that if a photon emerges at the top of the apparatus it appears that it had to have come by the path that leads to that point (blue line), and if it emerges at the side of the apparatus it appears that it had to have come by way of the other path (red line).

Next, as shown in the bottom diagram: a second beam splitter is introduced at the top right. It can direct either beam towards either path; thus note that whatever emerges from each exit port may have come by way of either path.

It is in this sense that the path information has been "erased."

2) If the 'Frankenstein-gadget' can handle the above: Would that mean that Chris & Dale are entangled both with themselves and each other? (Cool!)

I stop here and get back on the "Real stuff" later...


P.S. You didn’t collaborate with this guy, did you?
[PLAIN]http://middlezonemusings.com/wp-content/uploads/2008/03/abby-normal.jpg

 

[DrChinese]

Great 'Frankenstein-gadget' you got there DrC! I’m curious and do have questions:


1) I’ve quickly read the Eberly paper, and understood < 50% , but I must ask about your "polarizing beam splitter". In the paper Eberly describe the "Analyzer loop", as "Calcite analyzer" + "Reversed analyzer", and you have only 'one part' – the polarizing beam splitter? Wouldn’t that count as 'measurement' on Alice & Bob, 'destroying' the wavefunction/entanglement? If we compare with the http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser" the interference pattern is lost if we don’t apply another beam splitter to join the (virtual) paths of the photon:

[/PLAIN]

Why, yes, you are absolutely correct! I did indeed intend to represent the reverse components which would be needed to properly execute this. I guess I had realized that there might be several ways to accomplish this in practice, and failed to designate anything for handling this function. To be consistent with the reference, I should have placed the additional items in the diagram. I will see if I can upload something a bit tidier.

Thanks for pointing this out!

 

[DrChinese]

Here is some background, by the way, on which Eberly based his paper.

From French & Taylor, An Introduction to Quantum Mechanics, 1979:

 

[DrChinese]

Ok, here is an updated diagram, I hope this is a little better:

Creating Entangled "Frankenstein" Photons: Is this Possible?

 

[DevilsAvocado]

Ok, here is an updated diagram, I hope this is a little better:

Creating Entangled "Frankenstein" Photons: Is this Possible?

This looks much better! You know I’m basically 'guessing' here, but there is still one thing that might be a little 'troublesome'... and that’s polarizing in "polarizing beam splitter"...

I have no idea if this is correct – but my understanding of entangled photons is that the spin "of the pair" is actually null or nothing – it’s first when we do a measurement that a V/H spin is 'established'... Where did I read or hear this... I must check it out...?

But if the Eberly paper is correct, and if he runs the "polarizing beam splitter" with preserved entanglement, then your 'Frankenstein particles' must also work!

And if so – I think this is really amazing! If this works, it must lead to new possibilities in BTE!

Would be real interesting to hear what RUTA has to say about the technical validity of your 'Frankenstein-gadget'?


Edit1: I think I got it – you 'erase' the V/H spin in the "Reverse PBS" and THAT’S IT!


Edit2: But then the question arise – is there anything left of Alice & Bob's 'identity' after PBS...??

 

[DrChinese]

Would be real interesting to hear what RUTA has to say about the technical validity of your 'Frankenstein-gadget'?


Edit1: I think I got it – you 'erase' the V/H spin in the "Reverse PBS" and THAT’S IT!

Yup, the round trip would restore the original state and then the measurement results would be erased. Pretty fascinating, isn't it? In real life, I think you have to do things to preserve phase in the process or else there is destructive interference. (Not entirely certain though.)

 

[DevilsAvocado]

Pretty fascinating, isn't it?

I almost fell of my chair realizing this... I have had a thought in the back of my head in starting a new thread that would deal with the 'synchronization' of Alice & Bob (hoping to get around the interpretation business)... and here we have 'two ends' of an entanglement TOGETHER!?

What on Earth will happen if you run Chris thru another polarizing beam splitter?? This must settle the properties for 'two ends' of an entanglement INSTANTANEOUSLY??

... amazing ...

 

[madhatter106]

For some reason it makes me think of the holographic process when reading about the interferometer. Even our visual sight is based on two separate light paths.

I also was wondering how one splits what isn't? I'm not trying to play semantics. I understand the formalism, it's the wording that seems to cause confusion. Since the photon is 'energy' isn't polarization an induced magnetic state? If the photon is treated in that regard as a magnetic state then the polarization is just changing the electrical signature of the photons? and the entanglement is the shared magnetic state? although it would have to be a monopole right? odd bugger this energy signature.

 

[DevilsAvocado]

If the wavefunction is not real, then how do we explain this?

[PLAIN]http://www.sciencefriday.com/images/shows/2004/073004/AfsharExperimentSmall.jpg